Techniques to enable digital television and gps coexistence

ABSTRACT

An embodiment of the present invention provides an apparatus, comprising a digital television (DTV) receiver including at least a one-bit-flag such that when the flag is “on”, the DTV receiver is not allowed to start an initial acquisition process, and at least one additional receiver sharing part of a receive chain of the DTV receiver and wherein the additional receiver is capable of turning the one-bit-flag “on”. The flag may be set through communication between the drivers of the DTV receiver and the at least one additional receiver.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.11/642,316, entitled “TECHNIQUES TO ENABLE DIGITAL TELEVISION AND GPSCOEXISTENCE,” filed Dec. 19, 2006.

BACKGROUND

Digital television (DTV) is an emerging market today. Deployment ofterrestrial broadcasting began during 2005 and the market is currentlymoving toward handheld-oriented broadcast services that can withstandmobility of the receivers. DVB-H and T-DMB are going to be widelydeployed for mobile TV, whereas DVB-T is already widely deployed fornomadic-to-portable reception conditions.

Time slicing is a technology uniquely employed by DVB-H. It allows thetransmission to occur in time slots. The main objective of this featureis power saving at the receiver. However, all other standards (DVB-T,T-DMB, ISDB-T) do not have this mechanism and they rely on continuousreception conditions.

GPS is by now a well known technology that is widely exercised byhandheld/PDA devices. GPS is essentially supported in two modes:assisted and non-assisted. In assisted mode, the receiver gets the skymaps from source network (e.g., a cellular operator) and these mapstogether with measurements of timing and Doppler calculations allow thereceiver to determine precise location of the receiver. In non-assistedmode, the receiver has also to decode the sky maps from the satellitetransmissions. The non-assisted mode requires mostly reception in burststhat length around 1 minute or so. The assisted mode requires receptionof some hundreds of milliseconds, but only partially continuous. In anycase, the GPS receiver will need few milliseconds at least every now andawhile to perform reception.

A problem arises when the two subsystems share the radio/antennae suchthat when one subsystem is operational the other one cannot performreception.

Thus, a strong need exists for techniques to enable digital televisionand GPS coexistence.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed outand distinctly claimed in the concluding portion of the specification.The invention, however, both as to organization and method of operation,together with objects, features, and advantages thereof, may best beunderstood by reference to the following detailed description when readwith the accompanying drawings in which:

FIG. 1 illustrates an apparatus and system of an embodiment of thepresent invention; and

FIG. 2 is a flowchart of the method of an embodiment of the presentinvention.

It will be appreciated that for simplicity and clarity of illustration,elements illustrated in the figures have not necessarily been drawn toscale. For example, the dimensions of some of the elements areexaggerated relative to other elements for clarity. Further, whereconsidered appropriate, reference numerals have been repeated among thefigures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth in order to provide a thorough understanding of the invention.However, it will be understood by those skilled in the art that thepresent invention may be practiced without these specific details. Inother instances, well-known methods, procedures, components and circuitshave not been described in detail so as not to obscure the presentinvention.

Embodiments of the invention may be used in a variety of applications.Some embodiments of the invention may be used in conjunction withvarious devices and systems, for example, a transmitter, a receiver, atransceiver, a transmitter-receiver, a wireless communication station, awireless communication device, a wireless Access Point (AP), a modem, awireless modem, a Personal Computer (PC), a desktop computer, a mobilecomputer, a laptop computer, a notebook computer, a tablet computer, aserver computer, a handheld computer, a handheld device, a PersonalDigital Assistant (PDA) device, a handheld PDA device, a network, awireless network, a Local Area Network (LAN), a Wireless LAN (WLAN), aMetropolitan Area Network (MAN), a Wireless MAN (WMAN), a Wide AreaNetwork (WAN), a Wireless WAN (WWAN), devices and/or networks operatingin accordance with existing IEEE 802.11, 802.11a, 802.11b, 802.11e,802.11g, 802.11h, 802.11i, 802.11n, 802.16, 802.16d, 802.16e standardsand/or future versions and/or derivatives and/or Long Term Evolution(LTE) of the above standards, a Personal Area Network (PAN), a WirelessPAN (WPAN), units and/or devices which are part of the above WLAN and/orPAN and/or WPAN networks, one way and/or two-way radio communicationsystems, cellular radio-telephone communication systems, a cellulartelephone, a wireless telephone, a Personal Communication Systems (PCS)device, a PDA device which incorporates a wireless communication device,a Multiple Input Multiple Output (MIMO) transceiver or device, a SingleInput Multiple Output (SIMO) transceiver or device, a Multiple InputSingle Output (MISO) transceiver or device, a Multi Receiver Chain (MRC)transceiver or device, a transceiver or device having “smart antenna”technology or multiple antenna technology, or the like. Some embodimentsof the invention may be used in conjunction with one or more types ofwireless communication signals and/or systems, for example, RadioFrequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM),Orthogonal FDM (OFDM), Time-Division Multiplexing (TDM), Time-DivisionMultiple Access (TDMA), Extended TDMA (E-TDMA), General Packet RadioService (GPRS), Extended GPRS, Code-Division Multiple Access (CDMA),Wideband CDMA (WCDMA), CDMA 2000, Multi-Carrier Modulation (MDM),Discrete Multi-Tone (DMT), Bluetooth (RTM), ZigBee™, or the like.Embodiments of the invention may be used in various other apparatuses,devices, systems and/or networks.

Although embodiments of the invention are not limited in this regard,discussions utilizing terms such as, for example, “processing,”“computing,” “calculating,” “determining,” “establishing”, “analyzing”,“checking”, or the like, may refer to operation(s) and/or process(es) ofa computer, a computing platform, a computing system, or otherelectronic computing device, that manipulate and/or transform datarepresented as physical (e.g., electronic) quantities within thecomputer's registers and/or memories into other data similarlyrepresented as physical quantities within the computer's registersand/or memories or other information storage medium that may storeinstructions to perform operations and/or processes.

Although embodiments of the invention are not limited in this regard,the terms “plurality” and “a plurality” as used herein may include, forexample, “multiple” or “two or more”. The terms “plurality” or “aplurality” may be used throughout the specification to describe two ormore components, devices, elements, units, parameters, or the like. Forexample, “a plurality of stations” may include two or more stations.

As alluded to above, currently, when GPS and DTV share the same radio(same antenna or same receiver chain or same local oscillator etc.), theDTV reception may not be of good quality if the GPS has to operateperiodically at its normal time constants, since the DTV will go for aninitial acquisition process (that may take a long time and “freezes” thepicture) every time this happens.

In an embodiment of the present invention, with the proposedarchitecture, the cut in the DTV output shall last several orders ofmagnitude less than the current situation—a few milliseconds instead offew seconds. This will allow high quality user perceived concurrency.

Without some embodiments of the present invention, with GPSincorporated, it is likely that a serious damage to DTV viewing qualitywill occur. With embodiments of the present invention, it is possible toavoid this quality degradation.

It is understood that although some embodiments of the present inventionare illustrated using a global positioning system (GPS), the presentinvention is valid for any other technology in which resources areshared with digital TV and for which the DTV reception is deferred onlyfor short enough periods and not-frequent enough periods.

To understand the problem solved by the present invention, it isbeneficial to look at the numbers. DVB-T has blocks lasting between 200us to 1.8 ms; T-DMB has blocks lasting between 170 us to 1.3 ms etc. GPS(periodically) requires few milliseconds of receptions. Therefore,deferring the receive chain in favor of GPS results in DTV losing atleast several blocks. It is likely that in this case the DTV receiverwill declare “loss of signal” and will start an initial acquisitionstage. The initial acquisition stage for systems like DVB-T can last afew seconds (˜5 sec) because it requires the receiver to lock on a newfrequency and find the television channel of interest. The problemworsens when the acquisition starts examining frequencies other than theone the receiver is already locked on. If the initial acquisition stageis performed, and a 5 msec break in reception occurs, then the user willperceive a picture freeze or a blank screen. Of course, if thissituation happens periodically then DTV reception quality will bedramatically impacted, meaning that GPS and DTV cannot be operated“concurrently” practically.

DTV receivers may include mechanisms that allow them to keepsynchronization if the signal is lost for short durations; however theystart re-acquisition even for rather short interruptions because theycannot distinguish between deliberate temporary loss and non-deliberateloss of reception. In some embodiments of the present invention, it isassumed that the loss of signal period due to GPS (or other ‘concurrent’application sharing the receive chain) is short, but not short enough toavoid starting re-acquisition.

Turning now to the Figures, FIG. 1, shown generally as 100, provides aproposed architecture according to one embodiment of the presentinvention. Note that the instruction to the DTV driver can be obtainedalso from a “higher-layer-driver” if such exists. An embodiment of thepresent invention provides the inclusion of a one-bit-flag 135 at theDTV MAC layer such that when this flag is “on”, the DTV receiver is notallowed to start an initial acquisition process. The DTV driver 125, fedby the GPS driver 105, is the one responsible for turning this flag to“on” mode, via flag signaling GPS reception 130, when GPS acquisition isperformed and to “off” when GPS finishes its acquisition process (orsome short time after that). Thus, the DTV receiver will have a chanceto receive the signal back again on the same channel and the entirebreak in streaming should last a few milliseconds instead of fewseconds. In this case, it is expected that advanced video decoders willbe able to render the video stream perceived as error-free. GPSdemodulator 110 and DTV demodulator 120 are fed by GPS driver 105 andDTV driver 105 respectively. Connected to GPS demodulator 110 and DTVdemodulator 120 may be tuner 115 further connected to antenna 140.

Looking now at the flowchart of FIG. 2, is yet another embodiment of thepresent invention and provides a method, comprising including at least aone-bit-flag in a digital television (DTV) receiver at the DTV MAC layersuch that when the flag is “on”, the DTV receiver is not allowed tostart an initial acquisition process 210. Subsequently, at 220 thepresent method may further comprise sharing the same receive chain ofthe DTV by at least one additional receiver and adapting the at leastone additional receiver to coexist with the DTV. The at least oneadditional receiver may be a GPS receiver and the present method maystill further comprise including in the DTV receiver a DTV driver thatis fed by the GPS driver and is responsible for turning the flag to “on”mode when GPS reception is performed and to “off” when said GPSreception is powered down 230.

Some embodiments of the present invention may be implemented, forexample, using a machine-readable medium or article which may store aninstruction or a set of instructions that, if executed by a machine, forexample, by the system of FIG. 1, by the receiver in connection with aprocessor (not shown), or by other suitable machines, cause the machineto perform a method and/or operations in accordance with embodiments ofthe invention. Such machine may include, for example, any suitableprocessing platform, computing platform, computing device, processingdevice, computing system, processing system, computer, processor, or thelike, and may be implemented using any suitable combination of hardwareand/or software. The machine-readable medium or article may include, forexample, any suitable type of memory unit, memory device, memoryarticle, memory medium, storage device, storage article, storage mediumand/or storage unit, for example, memory, removable or non-removablemedia, erasable or non-erasable media, writeable or re-writeable media,digital or analog media, hard disk, floppy disk, Compact Disk Read OnlyMemory (CD-ROM), Compact Disk Recordable (CD-R), Compact DiskRe-Writeable (CD-RW), optical disk, magnetic media, various types ofDigital Versatile Disks (DVDs), a tape, a cassette, or the like. Theinstructions may include any suitable type of code, for example, sourcecode, compiled code, interpreted code, executable code, static code,dynamic code, or the like, and may be implemented using any suitablehigh-level, low-level, object-oriented, visual, compiled and/orinterpreted programming language, e.g., C, C++, Java, BASIC, Pascal,Fortran, Cobol, assembly language, machine code, or the like.

In an embodiment of the present invention the machine-accessible mediumthat provides instructions, which when accessed, may cause the machineto perform operations comprising including at least a one-bit-flag in adigital television (DTV) receiver at the DTV MAC layer such that whenthe flag is “on”, the DTV receiver is not allowed to start an initialacquisition process.

The machine-accessible medium may further comprise the instructionscausing the machine to perform operations further comprising sharing thesame receive chain of the DTV by at least one additional receiver andadapting the at least one additional receiver to coexist with the DTV;and yet may still further comprise the instructions causing the machineto perform operations further comprising including in the DTV receiver aDTV driver that is fed by the GPS driver and is responsible for turningthe flag to “on” mode when GPS acquisition is performed and to “off”when GPS finishes its acquisition process.

Some embodiments of the present invention may be implemented bysoftware, by hardware, or by any combination of software and/or hardwareas may be suitable for specific applications or in accordance withspecific design requirements. Embodiments of the invention may includeunits and/or sub-units, which may be separate of each other or combinedtogether, in whole or in part, and may be implemented using specific,multi-purpose or general processors or controllers, or devices as areknown in the art. Some embodiments of the invention may include buffers,registers, stacks, storage units and/or memory units, for temporary orlong-term storage of data or in order to facilitate the operation of aspecific embodiment.

While certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents may occur to those skilled in the art. It is, therefore, tobe understood that the appended claims are intended to cover all suchmodifications and changes as fall within the true spirit of theinvention.

1. An apparatus, comprising: a digital television (DTV) receiverincluding at least a one-bit-flag such that when said flag is “on”, theDTV receiver is not allowed to start an initial acquisition process; andat least one additional receiver sharing part of a receive chain of saidDTV receiver and wherein said additional receiver is capable of turningsaid one-bit-flag “on”.
 2. The apparatus of claim 1, wherein said flagis set through communication between the drivers of said DTV receiverand said at least one additional receiver.
 3. The apparatus of claim 1,wherein said at least one additional receiver is a GPS receiver andwherein said DTV driver is fed by a GPS driver and is responsible forturning said flag to “on” mode when GPS reception is performed and to“off” when said GPS reception is powered down.
 4. The apparatus of claim2, further comprising a video decoder adapted to render the video streamof said DTV to be perceived as error-free.
 5. The apparatus of claim 2,wherein said one-bit-flag communication between said DTV receiver andsaid at least one additional receiver is conducted through a thirddriver or controller.
 6. A method, comprising: including at leastone-bit-flag in a digital television (DTV) receiver such that when saidflag is “on”, the DTV receiver is not allowed to start an initialacquisition process; and sharing part of a receive chain of said DTVreceiver by at least one additional receiver and wherein said additionalreceiver is capable of turning said one-bit-flag “on”.
 7. The method ofclaim 6, further comprising setting said flag through communicationbetween the drivers of said DTV receiver and said at least oneadditional receiver.
 8. The method of claim 6, wherein said at least oneadditional receiver is a GPS receiver and wherein said DTV driver is fedby a GPS driver and is responsible for turning said flag to “on” modewhen GPS reception is performed and to “off” when said GPS reception ispowered down.
 9. The method of claim 7, further comprising using a videodecoder to render the video stream of said DTV to be perceived aserror-free.
 10. The method of claim 7, further comprising conductingsaid one-bit-flag communication between said DTV receiver and said atleast one additional receiver through a third driver or controller. 11.A machine-accessible medium that provides instructions, which whenaccessed, cause a machine to perform operations comprising: including atleast one-bit-flag in a digital television (DTV) receiver such that whensaid flag is “on”, the DTV receiver is not allowed to start an initialacquisition process; and sharing part of a receive chain of said DTVreceiver by at least one additional receiver and wherein said additionalreceiver is capable of turning said one-bit-flag “on”.
 12. Themachine-accessible medium of claim 11, further comprising saidinstructions causing said machine to perform operations furthercomprising setting said flag through communication between the driversof said DTV receiver and said at least one additional receiver.
 13. Themachine-accessible medium of claim 11, wherein said at least oneadditional receiver is a GPS receiver and wherein said DTV driver is fedby a GPS driver and is responsible for turning said flag to “on” modewhen GPS reception is performed and to “off” when said GPS reception ispowered down.
 14. The machine-accessible medium of claim 12, furthercomprising said instructions causing said machine to perform operationsfurther comprising using a video decoder to render the video stream ofsaid DTV to be perceived as error-free.
 15. The machine-accessiblemedium of claim 12, further comprising said instructions causing saidmachine to perform operations further comprising conducting saidone-bit-flag communication between said DTV receiver and said at leastone additional receiver through a third driver or controller.
 16. Themachine-accessible medium of claim 11, wherein said at least oneadditional receiver is a GPS receiver and wherein said DTV driver is fedby a GPS driver and is responsible for turning said flag to “on” modewhen GPS acquisition is performed and to “off” when said GPS finishesits acquisition process.
 17. A system, comprising: a GPS receiver; adigital television receiver (DTV) operable on the same receive chain assaid GPS receiver and including at least a one-bit-flag at the DTV MAClayer such that when this flag is “on”, the DTV receiver is not allowedto start an initial acquisition process thereby allowing said DTV andGPS receiver to coexist; and wherein said DTV receiver includes a DTVdriver, fed by the GPS driver and is responsible for turning this flagto “on” mode when GPS reception is performed and to “off” when said GPSreception is powered down.
 18. The system of claim 17, furthercomprising a video decoder adapted to render the video stream of saidDTV to be perceived as error-free.
 19. The system of claim 17, whereinsaid one-bit-flag communication between said DTV receiver and said atleast one additional receiver is conducted through a third driver orcontroller.